﻿using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Data;
using System.Data.Common;

namespace SY.DAL
{
    /// <summary>
    /// 抽象类
    /// </summary>
    public abstract class DBHelper
    {
       
        public abstract int ExecuteSQL(string sql);
        
        public abstract object ExecuteScalar(string sql);

       
        public abstract DbDataReader GetReader(string sql);

       
        public abstract DataTable GetTable(string sql);

        public abstract void Open();

        public abstract void Close();

        public static DBHelper get() 
        {
            return new SqlServerDBHelper();
        }
    }
}
